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CHAPTER 3: Operation
3. Operation
While the Provider and Subscriber Units are plugged in and receiving power, they
will operate continuously. Each Unit’s front-panel LEDs (which are also described
on its bottom label) will show you how it’s operating:
NOTE
When a Provider or Subscriber Unit is in Red, Yellow, or Blue Alarm, its
Ethernet link will be disabled and the Fast Ethernet LEDs (100, Act, and
Lnk) will be steadily lit.
• DS3 Lnk LED (green):
– If it’s flashing, the DS3 connection has been established and traffic is flowing
on the link.
– If it’s steadily lit, the DS3 connection has been established but no traffic is
currently flowing.
– If it’s dark, Red Alarm: The incoming DS3 connection has been lost and no
data is being received. If the outgoing connection from the Unit has also
been lost, the Unit at the other end will also be in Red Alarm.
• DS3 Alm LED (amber):
– If it’s dark, the DS3 connection is operating normally, unless the DS3 Lnk
LED is also dark, in which case a Red Alarm is occurring.
– If it’s steadily lit, Yellow Alarm: The outgoing DS3 connection has been lost
and no data is being transmitted. This means that the Unit at the other end
has lost incoming connection and is in Red Alarm.
– If it’s blinking once per second, Blue Alarm: An indirect connection has been
lost and the Unit might not be receiving data. This means that the Unit at
the other end has lost a connection with an intermediate device and is in
Red or Yellow Alarm.
• Power LED (green):
– If it’s steadily lit, the Unit is powered and operating.
– If it’s dark, and all other LEDs are also dark, the Unit isn’t receiving any
power or isn’t receiving enough power to operate. If any other LEDs are lit,
the Power LED is probably defective.